钝边的作用是防止接头根部焊穿。
参考答案:对
The teacher wanted ___ as correctly as possible.
A.that the work was done
B.the work done
C.that the work did
D.the work to do
汗液的主要成分有水分和无机盐等,因此人体在大量出汗时血液中丢失的主要成分有[ ]
A.血浆
B.水和血红蛋白
C.水分和部分无机盐
D.血细胞